I removed some very old linoleum from an old house I am remodeling. Underneath it had a black tarry sticky substance that adhered to the wood and I cannot get off. It seems to over time after being exposed to the air to harden and become unsticky. I am assuming it is the adhesive but I cannot get anything to remove it but it will chip off with a lot of elbow grease. Is there anything I can use to restore the beautiful oak flooring that is underneath it?...Thanks :)